Freon filling method and apparatus



March 19, 1957 Filed Sept. 28, 1954 A. B. MOJONNIER FREON FILLING METHODAND APPARATUS 2 Sheets-Sheet 2 FREON FILLING METHQD AND APPARATUS AlbertE. Mojonnier, Chicago, ill.

Application September 28, 1954, Serial No. 458,729

6 Claims. (Cl. 621) This invention relates to a method and. apparatusfor filling containers with. a measured. quantity of liquefied gas.

Various products, commonly referred to as aerosols, are presentlypackaged in pressurized containers with a compressed liquefied gas whichserves as a propellant.

The propellant used is a gas, such as Freon, which hasv a vapor pressurehigher than normal atmospheric pressure, at the temperature which theproduct is to be dispensed, so that the propellant maintains the productin the container under its elevated vapor pressure. When the dispensingvalve on the container is opened, the product is dispensed through thevalve under the pressure in the container.

The amount and type of propellant used varies with the product beingdispensed and it is therefore necessary to provide a dispenser which isadaptable to accurately dispense different quantities of propellant intothe container. One method of filling uses refrigeration to cool theingredients and the propellant to a temperature at which the propellantis a liquid at normal atmospheric pressures. This method is satisfactoryfor packaging ingredients which could be subjected to low temperatures:without freezing; it is not adaptable for loading. those productscontaining cold-sensitive. ingredients.

It has also been proposed to use a pressure filling apparatus forloading measured quantities of the propellant into the containers. Suchdispensers include a measuring cylinder and an adjustable stroke pistonfor discharging the propellant from the cylinder into the containerunder pressure. In order to dispense an accurately measured quantity, itis necessary that the measuring cylinder be filled with the propellantin its liquid form only, and not part liquid and part gas. In priorfillers, the propellant was introduced into the measuring cylinderdirectly from the shipping drums in which the propellant was under itsown vapor pressure. It has been ascertained that the propellant, underits own vapor pressure, partially expanded as it entered the measuringchamber and this pro duced variations in the quantity of propellantmeasured by the pressure filler and therefore caused variations in thequantity of propellant dispensed into the cans.

An important object of this invention is: the provision of an improvedapparatus for dispensing measured quantities. of a propellant intoaerosol containers.

Another object of this. invention is the provision of an apparatus, inaccordance with the foregoing object, which will dispense the propellantat the ambient. tempera ture so that the aerosol concentrate is notsubjected to freezing temperatures.

A further object of this invention is the provision of an apparatusincluding a pressure filler for dispensing. measured quantities ofpropellant into containers, with a novel pump apparatus for elevatingthe propellant pres sure befiore being introduced into the pressurefiller to a point well above the vapor pressure of the propellant at theambient temperature thereby preventing expansion of the propellant as itenters the pressure filler whereby the 2,785,537 Patented Mar. 19, 1957latter receives and dispenses an accurately measured quantity of thepropellant in its liquid form.

Still another object of this invention is the provision of an apparatus,in accordance with the foregoing object, in which the pump is operatedin accordance with the rate at which propellant isdispensed, therebypreventing re circulation of the propellant by the pump and consequentheating of the propellant.

These, together with various ancillary objects and advantages of thisinvention will be more readily appreciated, as the same becomes: betterunderstood, by reference to the following detailed description whentaken in connection with the accompanying drawings wherein:

Fig. l is a diagrarmnatickview of the propellant dispensing apparatus;

Fig. 2 is a longitudinal sectional view through the pressure dispenser;and

Fig. 3 is a longitudinal sectional View through the pumping apparatusfor delivering propellant under pressure to the filler.

Reference is now made more specifically to the accompanying drawings andin particular to Fig. 2 thereof wherein there is illustrated one type ofpressure filler 10 for filling the containers such as the can '1" (seeFig. 1) with propellant. The filler includes a crimper bell 11 having adownwardly facing opening 12 shaped to receive the upper end of thecontainer to be filled. Such con tainers, as fed to the filler I0, arepartially filled with aerosol concentrate and have a normally closeddispensing valve 8. The pressure filler is arranged to force thepropellant such as Freon, under pressure, through the container valveand into the container. The container valve recloses, after the externalpressure from the filler it) is released, and the propellant partiallyvaporizes in the container to establish its vapor pressure therein andmaintain the concentrate at that pressure.

A valve adapter i2, having. a valve engaging end 13 shaped to sealinglyengage the valve on the container, is removably disposed in the bore 14to permit interchanging of the valve adapters for the several differenttypes of dispenser valves on the containers. In the form of the fillershown in the drawings, the adapter has a flange 15' adapted to be seatedon the shoulder 16 and a check valve including a valve guide block 17 isdisposed in the bore 14 in overlying relation to the adapter. A valveplate 18 having a downwardly facing valve seat 19 is mounted in the bore1'4 and guidably supports the stem 21 of the valve 22. A spring 23' isprovided to normally urge the valve to its closed position and isarranged to permit opening of the valve when the pressure applied to theupper side: thereof exceeds a preselected value to be described morefully hereinafter.

The crimper bell 11 is attached to the lower end of the measuringcylinder 25' and communicates therewith through a passage 26. A piston27 is :reciprocably disposed in the cylinder and the piston rod 2-3thereof extends through the cylinder head 29. in order to selectivelyvary the amount dispensed by the filler, provision is made for adjustingthe piston stroke and for this purpose, the rod 28 is externallythreaded and carries a collar 2? which is adjustable therealong. Thecollar is locked in its adjusted position by a plug and set screwassembly 31 and is arranged to engage the cylinder head on thedispensing. stroke of the filler to limit the downward travel. of thepiston and thus control the amount of propellant dispensed in. eachstroke. Alternatively, the filler could. be arranged to adjustably limitthe travel of the piston on the upstroke thereof duringwhich themeasuring. cylinder is filled. Propellant is introduced into themeasuring cylinder from a conduit 33 which communicates with atransversepassage S5 at the upper end of the rod, an axial passage 36 beingprovided in the nod and piston to communicate passage 35 i with themeasuring cylinder.

The piston 27 is reciprocated in any desired manner and, as shown in thedrawings, is connected through a coupling 38 to the piston rod 39 of apneumatically operated motor 41 (see Fig. 2).

, Heretofore, the liquefied gas propellant has been introduced into themeasuring cylinder directly from the shipping drums in which thepropellant is in liquid form under its vapor pressure. When fillingcontainers in this manner, variations in the quantity of propellantdispensed into the cans by the filler was noted. This was determined tobe caused by the vaporization of a portion of .the liquefied gas as itwas introduced into the measuring cylinder. Therefore, at the start ofthe filling cycle, the measuring cylinder was only partly filled withliquefied gas, the remainder being the vaporized propellant. When thefiller piston was thereafter moved in a dispensing stroke, the vaporizedpart of the gas was merely compressed, and a charge of liquefied gas,less than the adjusted volume of the measuring cylinder, was introducedinto the cans.

In order to prevent this flashing of the liquefied gas as it enters thepressure filler, provision is made for compressing the liquefied gas, asit is taken from the. shipping drums, to a pressure Well above the vaporpressure of the gas under ambient temperatures. Consequently, the smallreduction in pressure on the liquefied gas, as it is fed into thepressure filler, is insufficient to lower the pressure on the propellantbelow the vapor pressure thereof, so that no expansion occurs.

As illustrated in Fig. 1, the liquefied gas is withdrawn by a pump 44from the shipping drum (not shown) through a conduit 45, shut-off valve46, check valve 47, and conduit 48. The check valve 47 is arranged topermit flow from the drum to the pump and closes to prevent return flow.A pressure gauge 49 is provided for checking the Freon supply pressure.The pump is driven by an hydraulic motor 52 which is arranged so thatthe operation of the pump is stopped when the discharge pressure reachesa preselected value. This eliminates the necessity of bypassing theexcess pump discharge fluid, when the discharge pressure reaches apreselected maximum, as occurs in continuously operated pumps. Suchby-passing of the discharge of the pump causes heating of the fluidpassing through the pump and, in the case of the liquefied gases, wouldtend to increase the vaporization of the propellant as it entered thefiller, thereby reducing advantages of compression in the pump.

The compressor pump 44 illustrated is a reciprocating type pump and thefluid motor used for operating the pump is also of the reciprocatingtype, it being understood that other pump and motor arrangements, suchas a rotary type fluid pump and a rotary fluid motor, may also be used.The pump 44 is of conventional construction and includes a cylinder 53communicated at its lower end with propellant inlet conduit 48. A piston54 is disposed in the cylinder and carries a poppet valve 55 arranged toclose on the up-stroke of the piston and to close on the down-stroke ofthe piston. The piston is connected by a piston rod 58to a tube 59having a sealed lower end 61, which tube extends through the packinggland 62 at the upper end of the pump cylinder 53. The pump is of thedouble acting type and the tube 59 has a smaller crosssection than thepump cylinder53 so that on the up-stroke of the pump, a volume of thefluid above the piston 54, equal to the difierential in thedisplacements of the piston 54 and the tube 61, is delivered through thepump discharge passage 63. On the downstroke of the pump, the fluidbelow the piston is forced through passage 56 ports 57 in the piston.The tube 59 entering the pump cylinder displaces a volume of the fluidabove the pump cylinder equal to the displacement of the tube.

The fluid motor is conveniently directly connected to the pump andincludes a cylinder 71 connected by legs 72 to the upper end of the pumpcylinder. The tube 59 extends upwardly through the sealing ring "it?into the motor cylinder and is formed with a valve seat 73 at the upperend thereof. A piston head 74 is secured to the upper end of the tubeand has passages 75 extending therethrough. A double acting valve ismounted on the piston head and includes an annular flanged valve ring 76slidably mounted on the piston head arranged to close the ports 75 whenthe ring is raised. The ring is connected by rods 77 to an exhaust valve78 which cooperates with the valve seat 73 to control fluid flow throughthe tube 59 to the exhaust ports 79 located intermediate the endsthereof. A spring 81 is located adjacent the upper end of the motorcylinder and engages the exhaust valve 78, when the piston reaches theupper end of its stroke, to close the exhaust valve and move the valvering 76 away from ports 75 to open the latter Compressed air, which isprovided from a suitable compressor through air inlet conduit 82 (seeFig. 1), an adjustable pressure regulator 83, shut-off valve 84 andconduit 85, then flows through ports 75 into the motor cylinder abovethe piston head 74. This forces the piston head '74- and tube 59 down.When the piston head reaches the lower end of its stroke, a disk 86carried by the piston head engages the lower end of the motor cylinderand moves the valve ring 76 upwardly to close the ports 75 and open theexhaust valve 78. The compressed air then urges the piston headupwardly.

The pressure developed by the pump is thus determined by the airpressure supplied to the fluid motor and the relative areas of thepistons in the fluid motor and pressure pump. In the apparatusillustrated, the areas of the two pistons are made equal so that thefluid motor will operate the pressure pump until the discharge pressureon the propellant delivered by the pump equals the air or other fluidpressure applied to the motor. Under those conditions, the pressuredeveloped by the motor equals the opposing pressure in the pump, and themotor operation stops. As soon as the pump discharge pressure isreleased, as when propellant is delivered to the filler, the pump willagain operate to maintain proper pressure on the propellant.

The pump apparatus is so arranged as to permit adjustment of thedischarge pressures on the propellant, as is necessary in the handlingof propellants having different vapor pressures. This is achievedwithout the necessity of regulating or otherwise throttling the pumpdischarge which would tend to cause heating of the propellant. Since themotor only operates until the pump discharge pressure equals the airpressure supplied to the motor, or bears a predetermined ratio theretodetermined by the areas of the pump and motor pistons, the pumpdischarge pressure is easily controlled by varying the pressure appliedto the fluid motor, as by the adjustable pressure regulator 83.

Provision is made for smoothing the pulsations from the pump 44. Theoutput of the pump is delivered through passage 63 and check valve 87,which is arranged to prevent return flow to the pump. The fluid flowingthrough the check valve passes through conduit 88 and through a manualshut-01f valve 89 to the upper end of an accumulating tank 91. Apressure gauge 92 is provided in the line 88 to permit checking of thepressure in the accumulating tank. The propellant from the lower end ofthe tank is passed through conduit 93, shut-off valve 94, conduit 95,check valve 96 and conduit 33 to the pressure filler. Check valve 96 isarranged to prevent return flow from the filler to the accumulatingtank.

An air cushion is provided in the accumulating tank 91 and for thispurpose, a charge of compressed air is supplied from the air compressor,through conduit 101, adjustable pressure regulator 102, shut-0E valve103 and bleed-off valve 104 to the top of the tank. A high pressurearenas? glass: gauge 105 is provided on the tank to permit checking theliquid level in the accumulating tank.

As previously described, the filler piston may conveniently be operatedby a pneumatic motor 41. As shown in Fig. 1, pressurized air issuppliedalternately to opposite ends of the motor cylinder-through conduit 107,multipleport valve 108 and conduits 109* and. 110. Valve 108 may be ofany conventional construction which, one position thereof, will applypressurized air fromconduit 107 to. conduit 110 and simultaneouslycommunicate conduit 109 to the exhaust conduit 111;, and which, in theother position thereof," connects. conduit 107 to conduit 109, andconnects conduit 110 to exhaust conduit 111. An air bleed-ofi valve 115is connected by conduit 116 to the passage 35 in the pressure filler topermit bleeding of air from the filler 10.

The operation of the pressure filling system will now be described infilling containers with a propellant such as Freon-12 which has a vaporpressure of about 70 p. s. i. at 70 F. The air regulator valve 83 is setto a preselected pressure such as 135 pounds per square inch gauge, wellabove the vapor pressure or the liquefied gas at the ambienttemperature. Valve 46 is then opened to allow the propellant to flowfrom the drum, through conduit 45 into the pressure pump 44 and valve 89is opened to allow propellant to flow from the pump to the accumulatingtank. Valve 84 is then opened to admit air to the fluid motor 52 whichoperates to fill the accumulating tank and compress the 'air above theFreon in the tank. When the accumulating tank has been filled to apreselected level, valve 84, which controls the supply of compressed airto the fluid motor 52, is closed to stop the motor. The valve 103 isthen opened and pressure regulator 102 set to apply head pressure on topof the liquefied gas in the tank, which pressure is measured on gauge92. Valve 84 is then reopened to apply air pressure to the fluid motor52 which operates until the propellant pressure in the accumulating tankis equal to the air pressure of 135 pounds per square inch gaugesupplied to the motor 52. Valve 94 is then opened and the propellantpermitted to flow to the filler. Valve 115 is then opened to bleed offany air in the filler and when the propellant begins to flowtherethrough, the valve is closed.

As the propellant flows into the filler 10, the measuring cylinder movesdownwardly under the pressure of the propellant until the piston 27reaches its upper limit. The pressure on the propellant then builds upin the measuring cylinder until it equals that in the accumulating tank,at which pressure the propellant is entirely in its liquid state. Thevalve 108 is then operated to apply air pressure to the fluid motor 41to urge the filler piston downwardly. During the initial portion of thestroke of the piston 28, the measuring cylinder moves with the pistonuntil the bell 11 engages the top of the container 7. Thereafter, thepiston 27 moves in the measuring cylinder to force the propellant pastcheck valve 22 and the container valve 8 into the container. As isapparent, spring 23 is designed to hold the valve 22 closed under thepressure of the propellant from the accumulator, and opens when thepressure in the filler is raised by the piston 27 during the dispensingstroke. Check valve 96 prevents the propellant from flowing from thefiller 10 to the accumulating tank, during the dispensing stroke, andopens on the up-stroke of piston 27 to admit another charge ofpropellant into the filler.

As the propellant is dispensed by the filler, the pressure in the tankis reduced. The air pressure applied to the motor 85 then exceeds thepressure on the propellant delivered by the pump whereupon the fluidmotor 52 operates to drive the pump 44 and replace the propellantwithdrawn from the tank. When it is desired to change the pressure onthe propellant in the accumulating tank, as when handling diiterentpropellants having different vapor pressures, the regulator 83 isadjusted to vary the air pressure supplied to the fluid motor which, inturn,

3 changes themaximum discharge pressure'of the pump 44. as previouslydescribed.

When it is desired to drain thesystem, the air and propellant inletvalves 84* and? 46 respectively are shut off. Valve103 is then openedallowing :air pressure from the main air supply line to force thepropellant out of the accumulating tank as it is dispensed by"thepressure filler 10. When theaccumulati-ng tank is empty, valve 103 isclosed and valve 104-opened to bleed-oflithe air pressure in the tankand. in the line to the pressure filler.

I claim:

1. In an apparatus for filling containers with a measured quantityofliquefied gas comprising, a pressure filler including a measuringcylinder and means including a piston in the cylinder for intermittentlydispensing a selectively variable quantity of liquid from the cylinderunder pressure, a pump for delivering the liquefied gas to the pressurefiller under a pressure greater than the vapor pressure of the liquefiedgas at the ambient temperature to prevent expansion of the liquefied gasas it enters the filler, a fluid motor operatively connected to saidpump to drive the latter, and means for applying fluid under apreselected pressure to the motor whereby the motor operates the pumpuntil the pump discharge pressure bears a predetermined relation to thefiuid pressure applied to the motor.

2. The combination of claim 1 wherein said means for applying pressureto said motor includes a pressure regulator which is selectivelyadjustable to vary the pressure applied to the motor and therebycorrespondingly vary the pump discharge pressure.

3. The combination of claim 1 including an accumulator tank connected tothe pump outlet to receive compressed liquefied gas therefrom and fordelivering the liquefied gas to the filler, and means for applyingpressure to the liquefied gas in the accumulator to maintain the gastherein at a pressure greater than the vapor pressure of the liquefiedgas at the temperature of the liquefied gas in the accumulator.

4. In an apparatus for filling containers at ambient temperature with ameasured quantity of liquefied gas comprising, a pressure filleroperable to measure and dispense a selectively variable quantity ofliquid under pressure, a pump for compressing the liquefied gas to apreselected pressure greater than the vapor pressure of the gas atambient temperature to prevent expansion of the liquefied gas as itenters the filler, an air motor operatively connected to said pump todrive the latter, an accumulator tank communicating with said pump toreceive compressed liquefied gas therefrom and for delivering theliquefied gas to the filler, means for supplying air under a preselectedpressure to said motor to thereby operate the pump until the pumpdischarge pressure bears a predetermined relation to the air pressureapplied to the motor and the latter stops, and means for introducing acharge of air under pressure into said accumulator tank to maintain theliquefied gas therein at said preselected pressure.

5. The method of supplying liquefied gas from a shipping drum containingthe gas under its vapor pressure to an intermittently operated fillingapparatus arranged to measure a quantity of liquid under pressure anddispense the same comprising, passing the gas from the drum through acompressor to the filling apparatus, operating the compressor with afluid motor to compress the gas and completely liquefy the same, andregulating the pressure on the fluid supplied to the fluid motor to avalue such that the output torque of the fluid motor equals the torquerequired to operate the compressor when the compressor dischargepressure is a preselected pressure above vapor pressure of said gas atambient temperatures.

6. The method of supplying liquefied gas from a shipping drum containingthe gas under its vapor pressure to an intermittently operated fillingapparatus arranged to measure a quantity of liquid under pressure anddis- '7 pense the same comprising, passing the gas from the drum to acompressor, operating the compressor with a fluid motor to compress thegas to a preselected pressure above the vapor pressure of the gas atambient temperature and completely liquefy the same, accumulating theliquefied gas from the compressor in a confined zone having a capacitywhich is small as compared to that of the drum, maintaining theliquefied gas in the confined zone under the pneumatic pressure of a gaswhich is gaseous at the temperature and pressure of the liquefied gas inthe zone, regulating the pressure on the fluid supplied to the motor toa value such that the output torque of the motor equals the torquerequired to operate the compressor when the til compressor dischargepressure equals said preselected pressure, and passing the liquefied gasfrom said zone to the gas at said preselected pressure.

References Cited in the file of this patent UNITED STATES PATENTS Re.19,054 Heylandt Jan. 16, 1934 2,252,300 McGrath Aug. 12, 1941 2,252,939McCoy Aug. 19, 1941 2,387,894 Fannin Oct. 30, 1945 2,641,399 McBean June9, 1953 2,670,605 Van Zandt et a1. Mar. 2, 1954

